The present invention generally relates to electric stringed musical instruments and, more specifically to an apparatus and method for replicating the sound of an acoustic stringed musical instrument with an electric stringed musical instrument.
It is well known that electric and acoustic guitars have different sounds. One of the more notable differences between the two types of guitars is the natural volume generated by each instrument. Guitar makers and players have searched for ways to increase the volume of the acoustic guitar. The advent of electronic amplification was one of the first and most successful innovations for building a louder guitar.
An acoustic guitar produces sounds in accordance with the striking of strings that causes the strings to vibrate. The energy from the vibrating strings is transferred to the soundboard of the guitar through the guitar""s bridge. An acoustic guitar""s hollow body amplifies the sound of the vibrating strings. However, the maximum volume achievable in an acoustic guitar may be insufficient in some instances, as the sound is unamplified. The aesthetic sound and timbre generated by the acoustic guitar, however, is often preferred because of its distinctiveness.
An electric guitar typically has a solid or mostly solid body because, unlike an acoustic guitar, the body of an electric guitar is typically not used for amplifying the sound produced by the vibrating strings. Instead, an electric guitar usually employs an electrical transducer, referred to as a pickup system, to detect the movement of the strings. Various types of pickup systems may be used in electric guitars to sense the vibration of the strings at various points and according to various methods. Such pickup methods include piezoelectric sensors as well as single and double coil transducer sensors. These pickup systems sense the string vibrations and convert them into electrical signals that are communicated to an amplifier for increasing the volume of the sound of the vibrating strings.
The electrical pickup systems in electric guitars generally do not model the sound of acoustic guitars, but rather produce a greatly modified sound corresponding to the string""s pure tones. However, the tone of the strings of an electric guitar generally does not model the tone of the strings of an acoustic guitar, which in large part, accounts for the different sound in each instrument. For example, if the strings of an acoustic guitar are struck with greater intensity, the sound emitted from the acoustic guitar is greater. While the same phenomenon occurs to some degree with an electric guitar, it does not approach the scale of amplification that is realized in an acoustic guitar, even when xe2x80x9cplugged in.xe2x80x9d Stated another way, unlike an acoustic guitar, striking the strings of an electric guitar with a greater intensity does not result in a proportionally amplified sound.
With the advent of electric guitars, many attempts have been made to make the sound of the electric guitar conform to, or model, the sound of an acoustic instrument, however, with little success. One prior attempt has involved using a single piezoelectric bridge pickup (with and without frequency shaping) to generate an acoustic like tone from an electric six-string or bass guitar. The sound with a single piezoelectric bridge pickup is generally superior to the sound of an electrical pickup, such as a single or dual coil transducer pickup; however, it does not emulate the acoustic sound properly. Moreover, a problem exists in modeling the proper amplification of sound resulting from the harder playing dynamics of the electric guitar. As a result, a heretofore-unaddressed need exists in the industry to address the aforementioned deficiencies.
One embodiment, among others, of the apparatus and method for modeling an acoustic sound in an electric stringed musical instrument, such as an electric guitar, includes a bridge sensor configured to sense string vibrations at the bridge of the instrument so that a bridge signal is generated in accordance with the vibrating strings. One or more body sensors, which may be positioned at different points on or within the body of the instrument, sense the resonance due to the string vibrations. The body sensors generate a body resonance signal in accordance with the sensed resonance. An amplification circuit amplifies the body resonance signal when the amplitude of bridge signal exceeds a first predetermined level. In addition, a second amplification circuit amplifies the bridge signal. A summing circuit adds the amplified body resonance signal with the amplified bridge signal to produce an output signal that upon replication as sound models the sound of an acoustic instrument.